The present invention relates to a method of producing reflectors from glass or glass ceramics wherein a reflector being open to the outside having a closed bottom is molded in a mold at a temperature above the transformation temperature and an opening is then punched out from the bottom.
A method of that kind is known from US 2004/0264200 A1.
A reflector consisting of glass is initially produced in this case by molding a gob in a mold whereafter its bottom area is heated up locally using a burner so that an opening can then be punched out from the bottom, in the softened state of the glass, using a ram and a die. The reflector is then fire-polished to make the surface sufficiently smooth.
Alternatively, the opening in the bottom area can be produced by drilling. In that case as well, a fire-polishing step is carried out subsequently in order to produce a smooth surface.
It has been found that while a smooth surface is guaranteed in the bottom area of reflectors that have been produced according to the known method, the tolerances regarding the opening produced frequently cannot be maintained without a secondary treatment.